Solve the following by describing a picture, and by constructing a graph:

1.  If your total earnings up to week 7 are 92.06094 dollars, and your total earnings up to week 15 are 106.0609 dollars, then what are your average earnings per week? Why do we say average earnings per week rather than just earnings per week?

2.  If an automobile is at milepost 165.4767 after having traveled for 4 hours and at milepost 209.4767 after having traveled for 10 hours, then what is its average speed? Why do we say average speed rather than just speed?

3.  If the water in a uniform cylinder has depth 131.9764 cm at clock time 5 seconds and depth 158.9764 cm at clock time 16 seconds, then at what average rate is the depth changing? What we say average rate rather than just rate?

4.  If you are earning money at an average rate of 13 dollars per week, and if at the end of week 6 your total earnings are 76.30537 dollars, then what will be your total earnings that the end of week 16?

5.  If an automobile is traveling at the rate of 67 mph, and is at milepost 389.6872 after having traveled for 6 hours, then what milepost would be after having traveled for 13 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 6 cm/second between clock times 9 s and 20 s, and if its depth at clock time 9 seconds is 38.12665 cm, then what is its depth at clock time 20 seconds?

7.  If your total earnings up to week 10 are 128.3975 dollars, and if you earn money at a constant rate of 13 dollars per week, then at what week will your total earnings be 141.3975 dollars?

8.  If an automobile is traveling at the rate of 70 mph, and is at milepost 485.6916 after having traveled for 7 hours, then after how many hours of travel will it have reached milepost 16?